362 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



c 1 . P, with 10-11 segments, 3.5 mm. long; pinnules in the proximal portion of the arms with 

 conspicuously flaring and overlapping distal ends, appearing very rough; smaller, arms 45 

 mm. long; cirri with 10 segments (southwestern Japan; 180-243 meters). 



hepburniona (p. 368) 



STROTOMETRA ORNATISSIMUS A. H. Clark 



Plate 20, Figure 65 

 [See also vol. 1, pt. 1, figs. 101, 102, p. 163.] 



Slrotometra ornatissimus A. H. Clark, Proc. Biol. Soc. Washington, vol. 25, 1912, p. 82 (description; 

 Siboga station 122) ; Unstalked crinoids of the Siboga-Exped., 1918, p. ix (ornamentation), p. 191 

 (in key; range), p. 192 (detailed description; station 122), fig. 10, p. 192, fig. 11, p. 193, p. 273 

 (listed), pi. 24, fig. 70. 



Strotometra ornatissimns A. H. Clark, Unstalked crinoids of the Siboga-Exped., 1918, p. 191. 



Diagnostic jeatures. — The distal edge of the second and fourth, and to a lesser 

 extent the fifth, brachials is everted and produced at right angles to the longitudinal 

 axis of the arm, standing up as a high, thin, rounded or fan-shaped crest; the axillaries 

 are chevron-shaped instead of triangular; and the fourth and fifth cirrus segments are 

 about three times as long as the median width, strongly constricted centrally with 

 expanded distal ends. 



Description. — The centrodorsal is flattened-hemispherical, 2.5 mm. in diameter at 

 the base; the dorsal pole is slightly convex. The cirrus sockets are arranged in one and 

 a partial second marginal row. 



The cirri are about XV (there are 22 cirrus sockets but some are not full size) ; the 

 longest cirrus stump is 4.5 mm. long to the distal dorsal edge of the fifth (the last 

 remaining) segment. The first segment is about twice as broad as long; the second 

 has the median length about equal to the median breadth and is centrally constricted 

 with the distal border produced, especially ventrally where it overlaps the proximal 

 end of the segment succeeding; the third is about twice as long as the proximal width, 

 strongly constricted centrally with the distal end prominent as in the second; the fourth 

 is about three times as long as the median width but otherwise similar to the third; 

 and the fifth is similar to the fourth but not quite so much constricted centrally and 

 hence appearing slightly broader in lateral view. 



The radials are just visible over the rim of the centrodorsal. The IBri are short, 

 about four times as broad as the median length, with the proximal border produced 

 into a thin straight margin and the lateral borders slightly more produced and turned 

 outward. The IBr 2 (axillaries) are broadly chevron-shaped with the lateral edges, 

 which are half again as long as those of the IBr 1; turned outward, unmodified, or with 

 two or three broad scallops; the lateral thirds of the proximal border are produced and 

 extended downward over the distal border of the IBi^; these have a scalloped or tuber- 

 cular edge which is nearly parallel to the concave distal edge opposite. The distal edges 

 of the axillaries are plain and unmodified. 



The 10 arms are about 40 mm. long. The first brachials have the proximal and 

 distal edges parallel, the outer edge slightly produced and faintly scalloped, and the 

 inner edges in apposition, in their distal half everted and scalloped; a corresponding 

 length of the inner portion of the distal edge is similarly everted and scalloped, and 

 the inner distal angle is rounded and produced into a thin rounded process with a more 

 or less scalloped border; the proximal border and the distal border except for the part 



